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This paper aims to analyse the relationship between the degrees of involvement of key design participants in the decision‐making process of refurbishment projects on the design performance.

The approach takes the form of a literature review of the published journals and textbooks along with a postal questionnaire with professional architects. In total 234 selected professional architects in Malaysia were involved in a postal questionnaire survey. A total of 82 questionnaires or 36 percent were identified as being fit to be used for the data analysis.

The degree of involvement of key participants are varied at all stages. Greater involvement of key participants is one of the ways to obtain more information on increased integration in the design process. Highest involvement of key design participants was found in the construction stage, which implies that more tasks need to be carried out in refurbishment projects. The involvement of an M&E engineer outside their normal domain in the design process could improve the design performance of refurbishment projects.

The literature review in the refurbishment design process was rather limited. Only limited study was carried out in specific areas owing to time and cost constraints.

The paper helps the project manager identify skills and professions that are important in the refurbishment design process, which could improve the completeness and accuracy of design product before work is started on site. This would help to reduce unnecessary design changes during the construction stage. The scale of fees for payment of the architect's services in refurbishment projects needs to be amended so that the amount paid up to contract documentation stage would be reduced from 70 percent to a more reasonable figure.

The paper determines the types of designers that are critically required in refurbishment projects, in order to have a more effective design process and thereby improve the accuracy and completeness of refurbishment design before work is started on site.

The paper provides an overview of research published in the innovation and operations management (IOM) literature on 15 methods for cost management in new product development, and it provides a comparison to an earlier review of the management accounting (MA) literature (Wouters & Morales, 2014).

This structured literature search covers papers published in 23 journals in IOM in the period 1990–2014.

The search yielded a sample of 208 unique papers with 275 results (one paper could refer to multiple cost management methods). The top 3 methods are modular design, component commonality, and product platforms, with 115 results (42%) together. In the MA literature, these three methods accounted for 29%, but target costing was the most researched cost management method by far (26%). Simulation is the most frequently used research method in the IOM literature, whereas this was averagely used in the MA literature; qualitative studies were the most frequently used research method in the MA literature, whereas this was averagely used in the IOM literature. We found a lot of papers presenting practical approaches or decision models as a further development of a particular cost management method, which is a clear difference from the MA literature.

This review focused on the same cost management methods, and future research could also consider other cost management methods which are likely to be more important in the IOM literature compared to the MA literature. Future research could also investigate innovative cost management practices in more detail through longitudinal case studies.

This review of research on methods for cost management published outside the MA literature provides an overview for MA researchers. It highlights key differences between both literatures in their research of the same cost management methods.

Cost estimation is one of the most significant steps in construction planning, which must be undertaken in the preliminary stages of any project; it is required for all projects to establish the project's budget. Confidence in these initial estimates is low, primarily due to the limited availability of suitable data, which leads the construction projects to frequently end up over budget. This paper investigated the efficacy of artificial neural networks (ANNs) methodologies in overcoming cost estimation problems in the early phases of the building design process.

Cost and design data from 104 projects constructed over the past five years in Jordan were used to develop, train and test ANN models. At the detailed design stage, 53 design factors were utilized to develop the first ANN model; then the factors were reduced to 41 and were utilized to develop the second predictive model at the schematic design stage. Finally, 27 design factors available at the concept design stage were utilized for the third ANN model.

The models achieved average cost estimation accuracy of 98, 98 and 97% in the detailed, schematic and concept design stages, respectively.

This paper formulated the aims and objectives to be applicable only in Jordan using historical data of building projects.

The ANN approach introduced as a management tool is expected to provide the stakeholders in the engineering business with an indispensable tool for predicting the cost with limited data at the early stages of construction projects.

The purpose of this paper is to assess the process of prefabricated construction (PC) and analyze the impacts of rework risk to identify the core tasks for which the rework risk has severe impacts.

The methods consist of a literature review, expert interviews, a questionnaire survey and a rework risk function. The expert interviews and questionnaire survey were administered to experts in the entire process of PC from the dimensions of rework frequency, rework cost and rework time. Descriptive and inferential statistics were employed to analyze the data. The rework risk function was based on the loss expectancy method.

There are 13 core tasks that have higher impacts than the average level. The core tasks in the design stage account for 100% of the tasks in the stage, those in the manufacturing stage account for 20% and those in the construction stage account for 23.1%. Compared with the other stages, the design stage is characterized by significantly more frequent rework, higher rework costs and longer rework time. The manufacturing stage is characterized by significantly higher rework costs than the construction stage. The manufacturing stage and construction stage are co-reliant, and both are impacted by the design stage.

The findings provide stakeholders with a clear understanding of the core tasks of the PC process and represent a method for identifying core tasks. Stakeholders can learn from this to focus on the core tasks to reduce rework risk and manage the process with the priority of PC rework management based on the following order: design > manufacturing > construction. The approach is suitable for core task identification in other areas.

This research provides insight into rework risk management and provides a novel analysis method for rework risk and PC management from the perspective of the construction process. The findings are valuable for supporting stakeholders in making effective construction plans to reduce the impacts of rework risk in PC and provide a reference for future research on process optimization.

The purpose of this paper is to identify factors affecting cost estimate accuracy in each of five design stages preceding building construction: order of magnitude, conceptual/schematic, detailed design, construction document and bid phase.

Data were collected using an online survey completed by 138 respondents who work in design consultancy firms in Jordan, including project managers, architects and quantity surveyors (QSs). Survey responses were analyzed using descriptive statistics. Confirmatory interviews and case study comparisons were used to confirm the statistical analysis results.

The results of this study indicated that each design stage’s cost estimate was affected by several factors. Two significant factors were common across four of the five design stages: client experience and project team experience. In addition, a high level of agreement was observed among the project managers, architects and QSs regarding the factors affecting cost estimate accuracy.

Accurately estimating building construction costs during the design process has posed a challenge for designers and their clients in Jordan. Despite the care and effort involved in preparing cost estimates in each of the five design stages, deviations are commonly observed. Because the accuracy of building construction cost estimates directly affect the success or failure of a project, the results of this study can be used to reduce uncertainties in building construction cost estimation and subsequently increase the likelihood of project success

Numerical simulations of a multistage multiphase pump at different operating conditions were performed to study the variational characteristics of flow parameters for each impeller. The simulation results were verified against the experimented results. Because of the compressibility of the gas, inlet volume flow rate qi and inlet flow angle ß_i for each impeller decrease gradually from the first to the last stage. The volume flow rate at the entrance of the pump q, rotational speed n and inlet gas volume fraction (IGVF) affect the characteristics of qi and ß_i.

The hydraulic design features of the impellers in the multistage multiphase pump are obtained based on the flow parameter characteristics of the pump. Using the hydraulic setup features, stage-by-stage design of the multistage multiphase pump for a nominal IGVF has been conducted.

The numerical simulation results show that hydraulic loss in impellers of the optimized pump is substantially reduced. Furthermore, the hydraulic efficiency of the optimized pump increases by 3.29 per cent, which verifies the validation of the method of stage-by-stage design.

Under various operating conditions, q_i and ß_i decrease gradually from the first to the fifth stage because of the compressibility of the gas. For this characteristic, the fluid behavior varies at each stage of the pump. As such, it is necessary to design impellers stage by stage in a multistage rotodynamic multiphase pump.

These results will have substantial effect on various practical operations in the industry. For example, in the development of subsea oilfields, the conventional conveying equipment, which contains liquid-phase pumps, compressors and separators, is replaced by multiphase pumps. Multiphase pumps directly transport the mixture of oil, gas and water from subsea oilwells through a single pipeline, which can simplify equipment usage, decrease backpressure of the wellhead and save capital costs.

Characteristics of a multistage multiphase pump under different operating conditions were investigated along with features of the inlet flow parameters for every impeller at each compression stage. Our simulation results have established that the change in the inlet flow parameters of every impeller is mainly because of the compressibility of the gas. The operational parameters q, n and IGVF all affect the characteristics of qi and ß_i. However, the IGVF has the most prominent effect. Lower values of IGVF have an insignificant effect on the gas compressibility. Higher values of IGVF have a significant effect on the gas compressibility. All these characteristics affect the hydraulic design of the impellers for a multistage multiphase pump. In addition, the machining precision should also be considered. Considering all these factors, when IGVF is lower than 10 per cent, all the impellers in the pump can be designed uniformly. When IGVF varies from 10 to 30 per cent, the first two stages should be designed separately, and the latter stages are uniform starting with the second stage. When IGVF varies from 30 to 50 per cent, the first three stages should be designed separately, and the latter stages are going to be similar to the third stage. An additional increase in IGVF results in degeneration of the differential pressure of the pump, which will reduce the compressibility of the gas. As such, it can be deduced that only the first three stages should be designed separately, and the latter stages will be similar to the third stage. In addition, for the pump working under a lower volume flow rate than 25 m³/h, the first three stages should be designed individually while keeping the geometrical structure of the subsequent stages the same as the third stage.

A robust method in environmental load assessment of buildings is urgently required to reduce the environmental burden of the construction industry. While the industry utilizes the life cycle assessment (LCA) method to assess environmental impacts of detailed designs, the implementation of changes at that late stage of development is often expensive and undesirable. On the other hand, during the early design stages, the LCA method is severely limited by the lack of information available, e.g., uncertainty about final materials to be used. This research study investigates how building information modeling (BIM) can facilitate LCA analysis at an early design stage.

A literature review is conducted to establish a framework for BIM and LCA integration, which creates the foundation for the development of a new BIM-based LCA tool. The tool is empirically evaluated on a large case study of a residential building in Denmark.

Case study results show that the new tool facilitates decision-making in an integrated design process, providing reliable LCA results on an early stage model, while avoiding intermediate manual input by the end user in contrast to other commercial LCA tools.

A first prototype of a BIM-based tool is demonstrated, which allows professionals, small architectural companies, students and researchers to calculate the environmental loads of the building in the early design stage in an automated, transparent and time-saving manner.

A number of techniques have been investigated (labelling and grouping, categorisation and importance level) to establish usable metrics for the quality management of the design process. The use of importance levels seemed to be the most effective method used with an adaptation of the value engineering technique but with the emphasis on worth rather than value (value being worth over cost). A partial validation of this technique has shown it to be useful in identifying the critical issues so that non‐value‐added processes can be eliminated.

A successful process of design concept evaluation has positive influence on subsequent processes. This study aims to consider the evaluation information at multiple stages and the interaction among evaluators and improve the credibility of evaluation results.

This paper proposes a multi-stage approach for design concept evaluation based on complex network and bounded confidence. First, a network is constructed according to the evaluation data. Depending on the consensus degree of evaluation opinions, the number of evaluation rounds is determined. Then, bounded confidence rules are applied for the modification of preference information. Last, a planning function is constructed to calculate the weight of each stage and aggregate information at multiple evaluation stages.

The results indicate that the opinions of the evaluators tend to be consistent after multiple stages of interactive adjustment, and the ordering of design concept alternatives tends to be stable with the progress of the evaluation.

Updating preferences according to the bounded confidence rules, only the opinions within the trust threshold are considered. The attribute information of the node itself is inadequately considered.

This method addresses the need for considering the evaluation information at each stage and minimizes the impact of disagreements within the evaluation group on the evaluation results.

The construction industry is shifting towards becoming more circular by reducing waste, reusing building materials and embracing regenerative solutions for energy generation and biodiversity conservation. Thus, construction professionals must perform diversified services to achieve a circular built environment (CBE). Implementing resource planning and waste management in CBE has already posed challenges to the quantity surveying profession; thus, quantity surveyors (QSs) should be equipped with new roles and competencies to tackle challenges in achieving a CBE. Hence, this study aimed to investigate the functions and competencies of QSs at the design and building material sourcing stages in achieving a CBE according to 3R principles.

The research apprehended a qualitative approach, including two expert interview rounds adhering to the Delphi technique with 14 and 11 experts per each round. Manual content analysis was incorporated to analyse the collected data.

The research findings revealed the important roles and competencies of QSs in achieving a CBE. In addition, essential functions and competencies were categorised according to the 3R principles (reduce, reuse, recycle) to successfully implement CBE during the Design and Building Material Sourcing stages. According to the 3R principles of CBE, cost control, cost planning, feasibility studies, measurement and quantification, risk management, value engineering and innovations and technologies were well-received by most interviewees as essential roles of QSs during the Design and Building Material Sourcing stages. Further, basic/mandatory competencies (personal, interpersonal, professional practice and business skills), economic analysis, BIM management, cost management and risk management are highly regarded by experts for QS as important competencies to achieve CBE.

With new construction trends, QSs must enhance their conventional roles and competencies and search for new skills and competencies. Those skills and competencies could be linked to the CE concept, either directly or indirectly. Since QS holds a prominent place in sustainable construction in CBE, adapting to changes in the construction industry such as CBE is timely for QSs. Further, there is a shortage of literature regarding QSs' roles and competencies in achieving a CBE; thus, this study will contribute by identifying new avenues for QSs in achieving a CBE in the practice and the research.